| Message ID | 20200304203330.4967-20-maz@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | irqchip/gic-v4: GICv4.1 architecture support | expand |
Hi Marc, On 3/4/20 9:33 PM, Marc Zyngier wrote: > In order to let a guest buy in the new, active-less SGIs, we > need to be able to switch between the two modes. > > Handle this by stopping all guest activity, transfer the state > from one mode to the other, and resume the guest. Nothing calls > this code so far, but a later patch will plug it into the MMIO > emulation. > > Signed-off-by: Marc Zyngier <maz@kernel.org> > --- > include/kvm/arm_vgic.h | 3 ++ > virt/kvm/arm/vgic/vgic-v4.c | 94 +++++++++++++++++++++++++++++++++++++ > virt/kvm/arm/vgic/vgic.h | 1 + > 3 files changed, 98 insertions(+) > > diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h > index 63457908c9c4..69f4164d6477 100644 > --- a/include/kvm/arm_vgic.h > +++ b/include/kvm/arm_vgic.h > @@ -231,6 +231,9 @@ struct vgic_dist { > /* distributor enabled */ > bool enabled; > > + /* Wants SGIs without active state */ > + bool nassgireq; > + > struct vgic_irq *spis; > > struct vgic_io_device dist_iodev; > diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c > index c2fcde104ea2..a65dc1c85363 100644 > --- a/virt/kvm/arm/vgic/vgic-v4.c > +++ b/virt/kvm/arm/vgic/vgic-v4.c > @@ -97,6 +97,100 @@ static irqreturn_t vgic_v4_doorbell_handler(int irq, void *info) > return IRQ_HANDLED; > } > > +static void vgic_v4_sync_sgi_config(struct its_vpe *vpe, struct vgic_irq *irq) > +{ > + vpe->sgi_config[irq->intid].enabled = irq->enabled; > + vpe->sgi_config[irq->intid].group = irq->group; > + vpe->sgi_config[irq->intid].priority = irq->priority; > +} > + > +static void vgic_v4_enable_vsgis(struct kvm_vcpu *vcpu) > +{ > + struct its_vpe *vpe = &vcpu->arch.vgic_cpu.vgic_v3.its_vpe; > + int i; > + > + /* > + * With GICv4.1, every virtual SGI can be directly injected. So > + * let's pretend that they are HW interrupts, tied to a host > + * IRQ. The SGI code will do its magic. > + */ > + for (i = 0; i < VGIC_NR_SGIS; i++) { > + struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, i); > + struct irq_desc *desc; > + int ret; Is is safe without holding the irq->irq_lock? > + > + if (irq->hw) { > + vgic_put_irq(vcpu->kvm, irq); > + continue; > + } > + > + irq->hw = true; > + irq->host_irq = irq_find_mapping(vpe->sgi_domain, i); > + > + /* Transfer the full irq state to the vPE */ > + vgic_v4_sync_sgi_config(vpe, irq); > + desc = irq_to_desc(irq->host_irq); > + ret = irq_domain_activate_irq(irq_desc_get_irq_data(desc), > + false); > + if (!WARN_ON(ret)) { > + /* Transfer pending state */ > + ret = irq_set_irqchip_state(irq->host_irq, > + IRQCHIP_STATE_PENDING, > + irq->pending_latch); > + WARN_ON(ret); > + irq->pending_latch = false; > + } > + > + vgic_put_irq(vcpu->kvm, irq); > + } > +} > + > +static void vgic_v4_disable_vsgis(struct kvm_vcpu *vcpu) > +{ > + int i; > + > + for (i = 0; i < VGIC_NR_SGIS; i++) { > + struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, i); > + struct irq_desc *desc; > + int ret; > + > + if (!irq->hw) { > + vgic_put_irq(vcpu->kvm, irq); > + continue; > + } > + > + irq->hw = false; > + ret = irq_get_irqchip_state(irq->host_irq, > + IRQCHIP_STATE_PENDING, > + &irq->pending_latch); > + WARN_ON(ret); > + > + desc = irq_to_desc(irq->host_irq); > + irq_domain_deactivate_irq(irq_desc_get_irq_data(desc)); > + > + vgic_put_irq(vcpu->kvm, irq); > + } > +} > + > +/* Must be called with the kvm lock held */ > +void vgic_v4_configure_vsgis(struct kvm *kvm) > +{ > + struct vgic_dist *dist = &kvm->arch.vgic; > + struct kvm_vcpu *vcpu; > + int i; > + > + kvm_arm_halt_guest(kvm); > + > + kvm_for_each_vcpu(i, vcpu, kvm) { > + if (dist->nassgireq) > + vgic_v4_enable_vsgis(vcpu); > + else > + vgic_v4_disable_vsgis(vcpu); > + } > + > + kvm_arm_resume_guest(kvm); > +} > + > /** > * vgic_v4_init - Initialize the GICv4 data structures > * @kvm: Pointer to the VM being initialized > diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h > index c7fefd6b1c80..769e4802645e 100644 > --- a/virt/kvm/arm/vgic/vgic.h > +++ b/virt/kvm/arm/vgic/vgic.h > @@ -316,5 +316,6 @@ void vgic_its_invalidate_cache(struct kvm *kvm); > bool vgic_supports_direct_msis(struct kvm *kvm); > int vgic_v4_init(struct kvm *kvm); > void vgic_v4_teardown(struct kvm *kvm); > +void vgic_v4_configure_vsgis(struct kvm *kvm); > > #endif > Thanks Eric
Hi Eric, On 2020-03-19 16:16, Auger Eric wrote: > Hi Marc, > > On 3/4/20 9:33 PM, Marc Zyngier wrote: >> In order to let a guest buy in the new, active-less SGIs, we >> need to be able to switch between the two modes. >> >> Handle this by stopping all guest activity, transfer the state >> from one mode to the other, and resume the guest. Nothing calls >> this code so far, but a later patch will plug it into the MMIO >> emulation. >> >> Signed-off-by: Marc Zyngier <maz@kernel.org> >> --- >> include/kvm/arm_vgic.h | 3 ++ >> virt/kvm/arm/vgic/vgic-v4.c | 94 >> +++++++++++++++++++++++++++++++++++++ >> virt/kvm/arm/vgic/vgic.h | 1 + >> 3 files changed, 98 insertions(+) >> >> diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h >> index 63457908c9c4..69f4164d6477 100644 >> --- a/include/kvm/arm_vgic.h >> +++ b/include/kvm/arm_vgic.h >> @@ -231,6 +231,9 @@ struct vgic_dist { >> /* distributor enabled */ >> bool enabled; >> >> + /* Wants SGIs without active state */ >> + bool nassgireq; >> + >> struct vgic_irq *spis; >> >> struct vgic_io_device dist_iodev; >> diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c >> index c2fcde104ea2..a65dc1c85363 100644 >> --- a/virt/kvm/arm/vgic/vgic-v4.c >> +++ b/virt/kvm/arm/vgic/vgic-v4.c >> @@ -97,6 +97,100 @@ static irqreturn_t vgic_v4_doorbell_handler(int >> irq, void *info) >> return IRQ_HANDLED; >> } >> >> +static void vgic_v4_sync_sgi_config(struct its_vpe *vpe, struct >> vgic_irq *irq) >> +{ >> + vpe->sgi_config[irq->intid].enabled = irq->enabled; >> + vpe->sgi_config[irq->intid].group = irq->group; >> + vpe->sgi_config[irq->intid].priority = irq->priority; >> +} >> + >> +static void vgic_v4_enable_vsgis(struct kvm_vcpu *vcpu) >> +{ >> + struct its_vpe *vpe = &vcpu->arch.vgic_cpu.vgic_v3.its_vpe; >> + int i; >> + >> + /* >> + * With GICv4.1, every virtual SGI can be directly injected. So >> + * let's pretend that they are HW interrupts, tied to a host >> + * IRQ. The SGI code will do its magic. >> + */ >> + for (i = 0; i < VGIC_NR_SGIS; i++) { >> + struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, i); >> + struct irq_desc *desc; >> + int ret; > Is is safe without holding the irq->irq_lock? The assumption here is that we're coming vgic_v4_configure_vsgis(), which starts by stopping the whole guest. My guess is that it should be safe enough, but maybe you are thinking of something else? Thanks, M.
Hi Marc, On 3/19/20 8:52 PM, Marc Zyngier wrote: > The assumption here is that we're coming vgic_v4_configure_vsgis(), > which starts > by stopping the whole guest. My guess is that it should be safe enough, but > maybe you are thinking of something else? I don't have a specific case in mind. Just preferred asking to make sure. Usually when touching those fields we take the lock (that's also the case in vgic_debug_show for instance). Thanks Eric
Hi Marc, On 2020/3/5 4:33, Marc Zyngier wrote: > In order to let a guest buy in the new, active-less SGIs, we > need to be able to switch between the two modes. > > Handle this by stopping all guest activity, transfer the state > from one mode to the other, and resume the guest. Nothing calls > this code so far, but a later patch will plug it into the MMIO > emulation. > > Signed-off-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Zenghui Yu <yuzenghui@huawei.com> Thanks
Hi Eric, On 2020-03-19 20:13, Auger Eric wrote: > Hi Marc, > > On 3/19/20 8:52 PM, Marc Zyngier wrote: >> The assumption here is that we're coming vgic_v4_configure_vsgis(), >> which starts >> by stopping the whole guest. My guess is that it should be safe >> enough, but >> maybe you are thinking of something else? > I don't have a specific case in mind. Just preferred asking to make > sure. Usually when touching those fields we take the lock (that's also > the case in vgic_debug_show for instance). Ah, good thing you mention the debug interface. I think it is the only thing that can run behind our back... Fair enough, I'll add the locking. Thanks, M.
diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h index 63457908c9c4..69f4164d6477 100644 --- a/include/kvm/arm_vgic.h +++ b/include/kvm/arm_vgic.h @@ -231,6 +231,9 @@ struct vgic_dist { /* distributor enabled */ bool enabled; + /* Wants SGIs without active state */ + bool nassgireq; + struct vgic_irq *spis; struct vgic_io_device dist_iodev; diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c index c2fcde104ea2..a65dc1c85363 100644 --- a/virt/kvm/arm/vgic/vgic-v4.c +++ b/virt/kvm/arm/vgic/vgic-v4.c @@ -97,6 +97,100 @@ static irqreturn_t vgic_v4_doorbell_handler(int irq, void *info) return IRQ_HANDLED; } +static void vgic_v4_sync_sgi_config(struct its_vpe *vpe, struct vgic_irq *irq) +{ + vpe->sgi_config[irq->intid].enabled = irq->enabled; + vpe->sgi_config[irq->intid].group = irq->group; + vpe->sgi_config[irq->intid].priority = irq->priority; +} + +static void vgic_v4_enable_vsgis(struct kvm_vcpu *vcpu) +{ + struct its_vpe *vpe = &vcpu->arch.vgic_cpu.vgic_v3.its_vpe; + int i; + + /* + * With GICv4.1, every virtual SGI can be directly injected. So + * let's pretend that they are HW interrupts, tied to a host + * IRQ. The SGI code will do its magic. + */ + for (i = 0; i < VGIC_NR_SGIS; i++) { + struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, i); + struct irq_desc *desc; + int ret; + + if (irq->hw) { + vgic_put_irq(vcpu->kvm, irq); + continue; + } + + irq->hw = true; + irq->host_irq = irq_find_mapping(vpe->sgi_domain, i); + + /* Transfer the full irq state to the vPE */ + vgic_v4_sync_sgi_config(vpe, irq); + desc = irq_to_desc(irq->host_irq); + ret = irq_domain_activate_irq(irq_desc_get_irq_data(desc), + false); + if (!WARN_ON(ret)) { + /* Transfer pending state */ + ret = irq_set_irqchip_state(irq->host_irq, + IRQCHIP_STATE_PENDING, + irq->pending_latch); + WARN_ON(ret); + irq->pending_latch = false; + } + + vgic_put_irq(vcpu->kvm, irq); + } +} + +static void vgic_v4_disable_vsgis(struct kvm_vcpu *vcpu) +{ + int i; + + for (i = 0; i < VGIC_NR_SGIS; i++) { + struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, i); + struct irq_desc *desc; + int ret; + + if (!irq->hw) { + vgic_put_irq(vcpu->kvm, irq); + continue; + } + + irq->hw = false; + ret = irq_get_irqchip_state(irq->host_irq, + IRQCHIP_STATE_PENDING, + &irq->pending_latch); + WARN_ON(ret); + + desc = irq_to_desc(irq->host_irq); + irq_domain_deactivate_irq(irq_desc_get_irq_data(desc)); + + vgic_put_irq(vcpu->kvm, irq); + } +} + +/* Must be called with the kvm lock held */ +void vgic_v4_configure_vsgis(struct kvm *kvm) +{ + struct vgic_dist *dist = &kvm->arch.vgic; + struct kvm_vcpu *vcpu; + int i; + + kvm_arm_halt_guest(kvm); + + kvm_for_each_vcpu(i, vcpu, kvm) { + if (dist->nassgireq) + vgic_v4_enable_vsgis(vcpu); + else + vgic_v4_disable_vsgis(vcpu); + } + + kvm_arm_resume_guest(kvm); +} + /** * vgic_v4_init - Initialize the GICv4 data structures * @kvm: Pointer to the VM being initialized diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h index c7fefd6b1c80..769e4802645e 100644 --- a/virt/kvm/arm/vgic/vgic.h +++ b/virt/kvm/arm/vgic/vgic.h @@ -316,5 +316,6 @@ void vgic_its_invalidate_cache(struct kvm *kvm); bool vgic_supports_direct_msis(struct kvm *kvm); int vgic_v4_init(struct kvm *kvm); void vgic_v4_teardown(struct kvm *kvm); +void vgic_v4_configure_vsgis(struct kvm *kvm); #endif
In order to let a guest buy in the new, active-less SGIs, we need to be able to switch between the two modes. Handle this by stopping all guest activity, transfer the state from one mode to the other, and resume the guest. Nothing calls this code so far, but a later patch will plug it into the MMIO emulation. Signed-off-by: Marc Zyngier <maz@kernel.org> --- include/kvm/arm_vgic.h | 3 ++ virt/kvm/arm/vgic/vgic-v4.c | 94 +++++++++++++++++++++++++++++++++++++ virt/kvm/arm/vgic/vgic.h | 1 + 3 files changed, 98 insertions(+)